2 'life-friendly' planets spotted by U.S. satellite

Sunday

Apr 21, 2013 at 12:01 AMApr 21, 2013 at 4:10 PM

An international team of astronomers has found two planets whose size and position suggest that they might support life. The planets orbit a star about 2,000 light-years away at the right distance for liquid water and, thus, life to exist, according to research published online by the journal Science.

An international team of astronomers has found two planets whose size and position suggest that they might support life.

The planets orbit a star about 2,000 light-years away at the right distance for liquid water and, thus, life to exist, according to research published online by the journal Science.

Compared with Earth, the planets, named Kepler-62e and Kepler-62f, are larger and receive 0.4 and 1.2 times the amount of solar radiation. The planet hunters, led by William Borucki of NASA, said they won’t know what the heavenly bodies look like or whether they are in fact habitable until they can further analyze their atmospheres.

“We have found two planets in the habitable zone of another star, and they are the best planets found to date” that might support life, said Borucki, a scientist in NASA’s Ames Research Center at Moffett Field in Mountain View, Calif.

One of the planets, Kepler-62f, might be a rocky celestial body with polar ice caps, Borucki said. The other, Kepler-62e, is thought to be warm and have lightning. While it’s too soon to know for sure, it might even be a water world, the first of its kind discovered, Borucki said.

“Kepler-62e probably has a very cloudy sky and is warm and humid all the way to the polar regions,” Dimitar Sasselov, an astronomer at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., and a co-author of the paper, said in a statement. “Kepler-62f would be cooler, but still potentially life-friendly.”

The planets were discovered using NASA’s Kepler satellite, a spacecraft launched in March 2009 with a mission to discover Earth-size and smaller celestial bodies in regions around their stars, particularly those where liquid water might exist. The spacecraft has found more than 2,700 planet candidates.

Kepler detects planets that cross in front of their stars, and gathers data that enables astronomers to estimate sizes and suggest composition.

In 2011, the Kepler mission found its first planet in the habitable zone, called Kepler-22b. That planet is larger than Earth and orbits a sunlike star every 290 days.